<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta http-equiv="X-UA-Compatible" content="IE=edge" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <script>
      //封装函数
      function exchange(a, b) {
        // 交换a和b的值
        temp = a
        a = b
        b = temp
        return `第一个数值${a},第二个数值${b}`
      }
      //调用函数，打印到页面
      document.write(exchange('one','two'))
      
    </script>
  </body>
</html>
